FRONTIER OIL CORPORATION LIST OF SUBSIDIARIES OF THE REGISTRANT Frontier Oil Corporation (incorporated in Wyoming) 662712 Alberta Ltd. (incorporated in Alberta) Wainoco Resources, Inc. (incorporated in Delaware), a subsidiary of Frontier Oil Corporation. Wainoco Oil & Gas Company (incorporated in Delaware), a subsidiary of Wainoco Resources, Inc. Frontier Holdings Inc. (incorporated in Delaware), a subsidiary of Frontier Oil Corporation. Frontier Refining & Marketing Inc. (incorporated in Delaware), a subsidiary of Frontier Holdings Inc. Frontier Refining Inc. (incorporated in Delaware), a subsidiary of Frontier Refining & Marketing Inc. Frontier Oil and Refining Company (incorporated in Delaware), a subsidiary of Frontier Refining & Marketing Inc. Frontier Pipeline Inc. (incorporated in Delaware), a subsidiary of Frontier Refining & Marketing Inc. Frontier El Dorado Refining Company (incorporated in Delaware), a subsidiary of Frontier Refining & Marketing Inc.